The Midwest and Great Lakes regions may experience "the coldest air in a generation" in the coming days, says the National Weather Service. A polar vortex sweeping the country will cause temperatures that will likely "shatter dozens of records." In Chicago, the temperature may come close to reaching a new record of 29 degrees below zero as residents are warned of "life-threatening extreme cold" that "can lead to rapid onset of frostbite and hypothermia," per The Washington Post. In the northern Plains, there are some areas where the wind chill will likely bring temperatures as low as 64 degrees below zero. The National Weather Service said that when outside in these areas, residents should "avoid taking deep breaths, and minimize talking."

The largest protest in Washington, D.C., since demonstrations against police brutality began following George Floyd's death has remained calm, despite a week of unrest across the country. As of 5 p.m. E.T. city police reportedly hadn't made a single arrest and reported no major incidents. The crowd of thousands gathered at the Lincoln Memorial earlier in the day and progressed toward Lafayette Square, where demonstrators were forcibly dispersed Monday so President Trump could walk through the area, and the White House. The nation's capital wasn't the only site of protests — they've continued in major cities, including New York, Atlanta, and Minneapolis, where Floyd was killed.

After several states, Washington, D.C., and Guam finished tallying Democratic primary votes this week, former Vice President Joe Biden has accrued enough delegates to clinch the party's presidential nomination, The Associated Press and CNN report. Biden has been the presumptive nominee since April, when his last remaining competitor, Sen. Bernie Sanders (I-Vt.) dropped out of the race, but he's now officially set to face off against President Trump in November's general election. Biden struggled in the primary's early stages, but a dominant performance in South Carolina — buoyed by the state's black voters — helped him rebound. “It was an honor to compete alongside one of the most talented groups of candidates the Democratic party has ever fielded, and I am proud to say that we are going into this general election a united party,” Biden said in a statement Friday.

Two Buffalo police officers, Robert McCabe and Aaron Torgalski, were both charged with one count of second-degree assault Saturday, prosecutors said, after they were seen on video Thursday shoving a 75-year-old man to the ground during protests against police brutality. The officers have pleaded not guilty and were released without bail. The video sparked outrage across the country, which intensified when the Buffalo Police Department said the protester, Martin Gugino, tripped and fell. Gugion was hospitalized with a head injury resulting from the fall. He is now in "serious, but stable condition" and is "progressing in his recovery." McCabe and Torgalski were suspended without pay Friday, prompting the 57 of their colleagues on the Buffalo Police Department's emergency response team to resign from the unit — but not the police force altogether — in their defense.

President Trump on Friday directed the Pentagon to permanently remove 9,500 of the 34,500 American troops stationed in Germany, The Wall Street Journal reports. A senior U.S. official said the move had been in the works since last September and was not related to recent disagreements between Trump and German Chancellor Angela Merkel. But the official did say the decision is consistent with Trump's frustration over the fact that Germany, a key member of NATO, doesn't meet the alliance's goal of spending 2 percent of its GDP on defense. A senior German defense official said Berlin hasn't been formally notified of the decision.

In response to demands from players this week, NFL Commissioner Roger Goodell said Friday the league now encourages players to "speak out and peacefully protest." The statement comes several years after former San Francisco 49ers quarterback Colin Kaepernick launched a movement to kneel during the national anthem before games. The protest against police brutality deeply divided the league at the time, and Kaepernick has remained unsigned since the 2016 season. But Goodell now says the league was "wrong for not listening to NFL players earlier." The reversal comes amid a wave of protests across the country, sparked by George Floyd's death while in police custody. Goodell said he is also personally protesting and wants "to be part of the much-needed change in this country."